The present invention relates to a driving gear in which the incoming torque is divided according to different paths of travel through the driving gears. In these driving gears, of typical aeronautical use but suitable for any application, use of gears of the type commonly known as "face gears" has been proposed, the geometry of which enables a ring gear to mesh with cylindrical pinions having their axis perpendicular to the ring gear axis. One example of this type of driving gears is for instance illustrated in U.S. Pat. No. 4,437,355, where several traditional bevel gears are adopted. One pinion carried by the power-input shaft meshes with two coaxial and facing ring gears also meshing with a second pinion rotating around an axis coplanar with the axis of the first pinion. The first pinion is mounted in a floating manner, so that the torque applied to its shaft is equally distributed between the two ring gears, in spite of the existence of definite size tolerances of the meshing teeth. U.S. Pat. No. 5,233,886 discloses a driving gear substantially having the same kinematic diagram as the one shown in the above-mentioned patent, in which gears of the "face gear" type are used. Known driving gears, as pointed out, enable a transmission of power distributed in accordance with different paths of travel, but they are rather bulky, heavy and of complicated accomplishment.
It is an object of the present invention to provide a driving gear of the type having a multiple power transmission path of travel, which is light-in-weight and of reduced bulkiness so that it is particularly, although not exclusively, useful in aeronautical constructions.